Wound dressings are used to clean, cover and protect wounds in order to facilitate the healing thereof. Absorbent wound dressings remove wound exudate, providing a clean, dry environment to promote healing while protecting the wound from the external environment. Absorbent wound dressings may also be used as wipes or swabs to cleanse skin, clean wounds or apply medicaments.
Wound dressings have customarily been made from textile fabrics such as woven gauze. The low absorbent capacity and low bulk of woven gauze required the use of multiple layers of folded material to achieve adequate performance. Disadvantages in the use of gauze as a direct wound covering were recognized in its relatively poor absorbency, lack of bulk and poor wound release characteristics.
Since the development of nonwoven technology beginning in the early 1950's, gauze dressings have been progressively replaced by nonwoven products. The nonwoven fabrics are superior to gauze in the areas of absorbent capacity, conformability, bulk, softness and low linting. Because of the superior absorbency, fewer layers of nonwoven material were required to construct a dressing having an absorbent capacity matching or exceeding that of the gauze counterpart. Thus, a 4-ply nonwoven sponge would effectively replace a 12-plY or 16-ply gauze sponge in most applications.
Because the nonwoven dressing required fewer layers of fabric for the desired degree of absorbency, lightweight wound dressings of 2- or 4-ply fabric often lacked the degree of bulk associated with 12- or 16-ply woven gauze. Thus the full benefit of the nonwoven product in protecting and cushioning the wound was not realized. To achieve higher bulk without increasing the amount of nonwoven material used in the dressings, some wound dressings were assembled with an outer cover of nonwoven fabric enclosing an inner filler of cellulosic tissue or carded staple fiber. Such combination products provided increased bulk and absorbency while retaining the advantages of a low linting, nonwoven fabric on the outer surface.
The present invention is directed to a nonwoven fabric having improved bulk, softness and absorbency for a given weight and construction. The present invention is also directed to the method for preparing such nonwoven fabrics and to wound dressings comprising such nonwoven material. These and other objects of the present invention will become apparent from the ensuing description and claims.